1. Field of the Invention
This invention broadly pertains to an appliance used in orthodontic treatment. More particularly, it pertains to an aesthetic orthodontic appliance that is at least partially removable.
2. Description of the Related Art
Orthodontics is the area and specialty of dentistry associated with the supervision, guidance, and correction malpositioned teeth into proper locations. Orthodontic treatment can be useful in correcting defects in a patient's bite (also called occlusion) along with promoting better hygiene and improving the overall aesthetics and health of the teeth.
Orthodontic treatment often involves the use of tiny slotted appliances known as brackets, which are generally affixed to the patient's anterior, cuspid, and bicuspid teeth. After the brackets have been placed on the teeth, an archwire is received into the slot of each bracket and acts as a track to guide the movement of respective teeth to orthodontically correct positions. End sections of the archwire are typically captured in appliances known as buccal tubes that are affixed to the patient's molar teeth. The brackets, archwires, and buccal tubes are typically referred to collectively as “braces”.
However, conventional braces have inherent limitations. For example, brackets and wires in the mouth tend to trap food and plaque, especially in areas behind the archwire and beneath bracket tiewings. The poor oral hygiene that results from plaque build up, in turn, can lead to a host of other problems, including tooth decay, gingivitis, periodontal disease, amongst others. Plaque build up in the vicinity of the brackets in particular can also cause decalcification and so-called “white spot” lesions on enamel surfaces that remain even after the braces are removed at the end of treatment.
Removable appliances can significantly alleviate some of these problems by providing an ability to remove the orthodontic appliance from the mouth while eating and/or brushing. Not only do removable appliances facilitate the maintenance and cleaning of the teeth, they also facilitate cleaning of the appliance. Popular removable appliances include polymeric aligner shells manufactured by Align Technology (Santa Clara, Calf.), which are intended to incrementally and progressively re-position teeth to a desired teeth arrangement. Other types of appliances include wire-embedded appliances such as those based on the Hawley retainer or Crozat appliance, which typically use metal wires that passively contact the teeth surfaces. While these appliances can be used to effect corrective tooth movements, they are most commonly used for retention of teeth after correction has been completed. Spring aligners, also called spring retainers, combine aspects of both clear aligners and wire-embedded retainers and can be used for orthodontic correction. However, these too are limited in the types of forces they can apply on teeth, which in turn impact the breadth of dental malocclusions that can be treated.